showcalendar on DateField by default

I'm generating almost all of my forms from the DataObjects I implemented by using the getFrontendFields-Function:

$fields = $dataObject->getFrontendFields();

Those fields include DateFields sometimes. I would like to use the integrated option for the 'showcalendar' without adjusting all fields manually. Does anyone know a way to set the configuration by default to true for the key 'showcalendar'?